Reformulated function to avoid binding eqn warning (maint 10)

mwetter · mwetter · commit 2fd34c88d5b8 · 2025-05-01T18:42:38.000-07:00
For #4215
diff --git a/Buildings/HeatTransfer/Conduction/BaseClasses/der_temperature_u.mo b/Buildings/HeatTransfer/Conduction/BaseClasses/der_temperature_u.mo
@@ -20,15 +20,17 @@ function der_temperature_u
     each unit="kg.K2/J")
     "Derivatives dT/du at the support points";
 protected
-  parameter Real scale=0.999 "Used to place points on the phase transition";
-  Modelica.Units.SI.Temperature Tm1=TSol + (1 - scale)*(TLiq - TSol)
+  constant Real scale=0.999 "Used to place points on the phase transition";
+  Modelica.Units.SI.Temperature Tm1
     "Support point";
-  Modelica.Units.SI.Temperature Tm2=TSol + scale*(TLiq - TSol)
+  Modelica.Units.SI.Temperature Tm2
     "Support point";
 algorithm
   assert(Buildings.HeatTransfer.Conduction.nSupPCM == 6,
     "The material must have exactly 6 support points for the u(T) relation.");
   assert(TLiq > TSol, "TLiq has to be larger than TSol.");
+  Tm1:=TSol + (1 - scale)*(TLiq - TSol);
+  Tm2:=TSol + scale*(TLiq - TSol);
   // Get the derivative values at the support points
   ud:={c*scale*TSol,
        c*TSol,
@@ -61,6 +63,12 @@ to compute for a given specific internal energy the temperature.
 revisions="<html>
 <ul>
 <li>
+May 1, 2025, by Michael Wetter:<br/>
+Reformulated model to avoid warning about binding equation not being a parameter expression.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/4215\">#4215</a>.
+</li>
+<li>
 August 30, 2024, by Michael Wetter:<br/>
 Removed wrong <code>parameter</code> declaration on a protected variable which causes an error in
 Dymola 2025x beta1.<br/>
diff --git a/Buildings/package.mo b/Buildings/package.mo
@@ -231,6 +231,16 @@ have been <b style=\"color:blue\">improved</b> in a
 <b style=\"color:blue\">backward compatible</b> way:
 </p>
 <table class=\"releaseTable\" summary=\"summary\" border=\"1\" cellspacing=\"0\" cellpadding=\"2\" style=\"border-collapse:collapse;\">
+<tr><td colspan=\"2\"><b>Buildings.HeatTransfer</b>
+    </td>
+</tr>
+<tr><td valign=\"top\">Buildings.HeatTransfer.Conduction.BaseClasses.der_temperature_u
+    </td>
+    <td valign=\"top\">Reformulated model to avoid warning about binding equation not being a parameter expression.<br/>
+                       This is for
+                       <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/4215\">#4215</a>.
+    </td>
+</tr>
 <tr><td colspan=\"2\"><b>xxx</b>
     </td>
 </tr>
